Sökning: "waveguides"

Visar resultat 1 - 5 av 95 avhandlingar innehållade ordet waveguides.

  1. 1. Numerical conformal mappings for waveguides

    Detta är en avhandling från Växjö : Växjö University Press

    Författare :Anders Andersson; Börje Nilsson; Michael Benedicks; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; waveguides; building block method; numerical conformal mappings; Schwarz–Christoffel mapping; rounded corners method; approximate curve factors; outer polygon method; boundary curvature; zipper method; geodesic algorithm; acoustic wave scattering; electro-magnetic wave scattering; MATHEMATICS Applied mathematics; MATEMATIK Tillämpad matematik;

    Sammanfattning : Acoustic or electro-magnetic scattering in a waveguide with varying direction and cross-section can be re-formulated as a two-dimensional scattering problem, provided that the variations take place in only one dimension at a time. By using the so-called Building Block Method, it is possible to construct the scattering properties of a combination of scatterers when the properties of each scatterer are known. LÄS MER

  2. 2. Schrödinger Operators in Waveguides

    Detta är en avhandling från Stockholm : KTH

    Författare :Tomas Ekholm; Timo Weidl; Ari Laptev; Pavel Exner; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Schrödinger Operators; Hardy Inequalities; NATURAL SCIENCES Physics Other physics Mathematical physics; NATURVETENSKAP Fysik Övrig fysik Matematisk fysik;

    Sammanfattning : In this thesis, which consists of four papers, we study the discrete spectrum of Schrödinger operators in waveguides. In these domains the quadratic form of the Dirichlet Laplacian operator does not satisfy any Hardy inequality. LÄS MER

  3. 3. Fluorinated polymer optical waveguides

    Detta är en avhandling från Institutionen för polymerteknologi

    Författare :Claire Pitois; [2001]
    Nyckelord :polymer; optical waveguide; telecommunications. Low-los passive wavguide; lithography; synthesis;

    Sammanfattning : .... LÄS MER

  4. 4. Miniaturized Hard Waveguides in Multifunction Array Antennas

    Detta är en avhandling från Institutionen för polymerteknologi

    Författare :Malcolm Ng Mou Kehn; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; interlaced arrays; Floquet theorem; reflector antennas; focal plane array; multifunction antennas; miniaturized waveguides; multilayer structures; spectral domain technique; periodic structures; aperture reuse; method of moments; soft and hard surfaces; array antennas;

    Sammanfattning : Recent advances in technologies of wireless communications systems have led to an increasing desire for several antennas performing diverse functions at different frequencies to be integrated into a common radiating aperture. This gives rise to the so-called multifunction antenna, which affords the saving of scarce premium real estate and can alleviate problems arising from excessive antenna protrusions in aspects such as aerodynamics, aesthetics, and stealth capability in military applications. LÄS MER

  5. 5. Horizontal Slot Waveguides for Silicon Photonics Back-End Integration

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Maziar A. M. Naiini; Mikael Östling; Jörge Schulze; [2014]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; silicon photonics; slot waveguides; grating couplers; CMOS tech- nology; high-k; ALD; germanium photodetectors; graphene photodetectors; pho- tonic integrated circuits;

    Sammanfattning : This thesis presents the development of integrated silicon photonic devices. These devices are compatible with the present and near future CMOS technology. High-khorizontal grating couplers and waveguides are proposed. LÄS MER